Method and apparatus for transmitting signals to locomotives and the like



Jan. 27. 1925. v 1,524,429

' H. GEWECKE METHOD AND APPARATUS FOR TRANSMITTING SIGNALS TO LOCOMOTIVES AND THE LIKE I Filed May 5, 1922 5 Sheets-Sheet 1 Fig. /Z.

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UNITED STATES PATENT OFFICE.

HERMANN GEWECKE, OF BERLIN, GERMANY.

METHOD AND APPARATUS FOR TRANSMITTING SIGNALS TO LOCOMOTIVES AND THE LIKE.

Application filed May 3,

To all whom it may concern:

Be it known that I, HERMANN GEWECKE, engineer, of German nationality, residing at 12 Hallesches Ufer, Berlin SW., Germany,

I have invented certain new and useful Improvements in Methods and Apparatus for Transmitting Signals to Locomotives and the'like; and I do hereby declare the following to be a full, clear, and exact description of the invention, of which the following is a specification.

The invention relates to a method and apparatusfor transmitting signals to travelling trains by means of electric oscillations.

In the use of the hitherto known devices of this kind, either the locomotive or the train has been fitted with a receiver which could be affected by an outwardly arranged transmitter. These installations have in particular the disadvantage that the senders arranged at the various block stations which are *bodily far apart must be provided with energy. A further disadvantage of the aforementioned devices consists in the fact that it is difficult to transmit a signal to a definite train only and not to all the trains within the range of th electric waves. A still further serious disadvantage of the hitherto known devices is that the receivers which are generally installed on the locomotive can be influenced by disturbances of strange senders, atmospheric disturbances or by masses of metal in the neighborhood of the line.

Similar to other solutions (except where the solutions are "carried out in a wireless way) of the problem of transmitting signals to travelling. trains, the present invention also utilizes the principle of weakening electric energy generated on the locomotive by auxiliary means arranged along the line. The invention involves a special mode of putting this principle into e'fi'ect. The hitherto known solutions according to this principle 'have the disadvantage that an unintended releasing of the signals may be caused to take place at certain places on the body of the line for example, by metal sleepers, points, or metal masses, such as over-line bridges and the like, in case the electrical installation on the locomotive is affected in a ferro-magnetic way, and that, furthermore, an effective influencing can 1922. Serial No. 558,304.

only occur at a very small distance between devices located on the locomotive and the body of the line respectively.

All disadvantages of the hitherto known solutions of this kind and also of the solutions of a wireless character are completely overcome according to the present invention by arranging on the locomotive of the travelling railway train a generator for electrical oscillations and at certain places on the body of the lin receiving circuits tuned to the frequency of these oscillations.

In the drawings which illustrate several exemplifications of the invention;

Fig. 1 shows an installation of apparatus according to the invention on a railway locomotiv and on the line;

Fig. 2 is a diagrammatic representation of the apparatus shown in Fig 1;

Figs. 3 and 4 show suitable installations comprising different ways of arranging the signalling devices of the installations;

Fig. 5 shows a cathode tube installation, comprising an arrangement for separating the transmitting element of the installation, arranged in the frame of the locomotive, from the producer of oscillations; which together with the signaling device is arranged 1n an easily accessible manner in the cab.

Figs. 6 to 8 show cathode tube installations with condensers for equalizing the cable capacity of the oscillating circuit; and

Figs. 9 to 11 show other modified forms of installations embodying the invention.

Fig. 12 shows an arrangement for signalling trains of diflerent classes at different distances from a stopping point.

In the exemplification of the invention shown in Fig. 1, A denotes a producer of oscillations, and B designates a devic in connection therewith for the releasing of signals or for the performance of other work. The device C in the frame of the locomotive acts as an electro-magnetic coupling between the producer of oscillations A and the line-element D. If C approaches D, as seen in Fig. 2, the energy of the producer of oscillations A acting on the inductorium C is altered by being coupled with the line circuit D tuned to its frequency. Thecharacter of the coupling between the coil devices C andD is such that the oscillating energy in A is changed so that the signalling device B is made to act. E and F denote switching devices which are in communication with the brake-lever of the locomotive or with a line signal respectively. The switches E and F; can be operated to render the installation ineffective. By means of suitable known line switching devices, any

of the line elements D can be rendered eflective or ineffective to initiate the operation ofthe signalling device B.

The use of electric oscillations for coordinating the element on the line and the device on the locomotive enables a sensitive tuning of the parts with regard to the freuency of oscillation to be obtained, with t 6 result that only an accurate receiving set on the locomotive tuned to the frequency of the line can receive the energy from the sender. The coordin'ation of the parts of the installation, in such an instance, is absolutely independent of the climatic ,conditions. There is thus assured an absolute freedom from disturbances for the action of the installation. As the apparatus of the line consists of a definite number of windings and of a fixed capacity, a withdrawal of ener from the oscillating circuit on the train by means of metal parts which may lie along the line and, in con sequence, an unintended response of the signalling 'aplparatus cannot occur, as transmission of igh frequency can take place between two circuits only when they are accurately tuned with regard to each other.

Asa generator of electric oscillations in the practice of the invention a cathode tube enerator A (Fig. 3) is especially suited. uitably the coupling of the cathode tube 1 with the circuit of oscillation 2 is so efi'ected that a relay-action is induced in -the generator, upon. withdrawal of energy from the oscillating circuit by the tuned circuit D in such a manner that the oscillations produced by the generator are stopped or at least much reduced. In comparison with other producers of oscillations such as Poulsons are light or an alternating current machine, the cathode-generator, in addition to the above-described relay-effect, ofl'ers still further advantages. As is well known, the arc-light must burn in a chamber filled with, hydrogen, so that an observation of the are light from the outside is impossible. Thus the engine-driver when a si nal has been given does not know, whether tie signal is due to a communication from the line or to a failureof the producer of oscillations. In the case of a cathode tube, if a signal is due ,to failure of the oscillation generator, such fact can be ascertained at once, as the conditions under which oscillations are produced by cathode tubes can be controlled at any time. If, for instance, the heating of the filament fails, the failure is apparent from their complicated mode of wor ing, the. 'consum tion ofthe carbon, etc., unintended oscillations of the are light, by reason of disturbances, occur'extremely often. 'Also the replacement of.a destroyed generator having .a cathode tube is much simpler than that of an are light generator. Moreover,

the cathode tube possesses the pro erty of producing constant oscillations w ich are absolutely essential for the resent purpose, whereas, the production 0 oscillations by means of an are light is subject to variations. The production of absolutely constant oscillationsand the previously mentioned relay action also. constitute important advantages of the use of a cathode generator over the use of alternating current machines, since the regulation of the revolutions of such machines oflers serious di% l:1ulties. H

e slgna 1n prises a relay B by the action of the oscillations in the' generator A. However, when the ener in the sender circuit is decreased or mappears by coupling of the generator A with the line element D, the relay releases its armature and closes a circuit in which an device B preferably comoptical or sounding signalling device is arranged. The response of the signalling device can be registered by a time recorder. As shown in F 1g. 3, the armature R of the relay B is connected in circuit with a bell T and time recorder V. From the registerings of the time recorder, on the one hand, the fault of the driver can be proved when he has runpast a stop signal although the apparatus responded properly, and, on the other hand, a failure of the installation can be ascertained.

The practical construction of the signaling device can be effected in various ways. Suitably (see Fig. 4) the relay B is urranged-in the anode-line of the cathode generator A so that upon cessation or reduction of the oscillations in the generator and the concomitant change in the anode-current, the relay armature is released and the desired signal is given. By. making the tubesand the oscillating circuits of suitable proportions, this alteration of the anode-current can be made particularly great, whereby a reliable response of the relay may be obtained.

The oscillations roduced in the enerator A are preferab y sent through a rame coil (see Fig. 1, apparatus C) which has the advantage that it sends out oscillations chiefly in one direction that is in the diwhich is normally arrested,

lit

rection of the planes of the windings of the coil. By using a corresponding frame coil for the receiver or line circuit D, the absorption of energy by this circuit can be considerably increased. For example if the coils C and D are arranged horizontally as shown in Fig. 1 of the drawings, with the frame coil C mounted on the locomotive so that its horizontal plane is close to the horizontal plane of the line coil D then' as coil C approaches the coil D in the movement of the locomotive and finally reaches a position directly above it,'there will be a large absorption of energy by the coil D from the coil C and therefore from the oscillating circuit on the locomotive. This absorption of energy will, of course, decrease the current flow in the signaling relay and cause it to close the signalling circuit.

As a suitable coil for the tuned oscillating circuit 1) arranged on the line an armored coil is, preferably, employed which is arran ed in such a manner that it is protected from becoming damaged by stones and the like. It may have the shape of an iron tube enclosing windings (see Fig. 1, D). In such a case, the tubular cover should not constitute a closed magnetic or electric circuit. This may, for instance, be achieved by disconnecting the iron tubular ring at one or several places and by closing it again at such places by means of an insulating material.

By constructin the oscillating system in the shape of rame coils a number of advantages are attained which are of special importance for the present purpose. Such advantages are: small space increase of the efl'ect, smallest losses of energy, greatest freedom from disturbance, and protection against mechanical or climatic influences. All these advantages combine to the important result of assurin the long-continued eficient operation of t e installation. I

When usingcathode tubes having back coupling as generators in ordinary intermediate circult installations in consequence of the arrangement of the tubes difficulties arise in practice with regard to the construction and the working of the apparatus in consequence of the arrangement of the tubes in direct proximity to the intermediate circuit. The present problem calls for the local separation of the intermediate circuit arts which, on the one hand, serve for the ack coupling and tuning and, on the other hand, for the coupling with the line element and also calls for the use of the most simple conduits for their connection. If ordinary cables were used for connecting the parts, the high cable capacity woul act in a disturbing manner as, when operating at short wave lengths, the available self induction of the intermediate circuit and the degree of coupling between it and the line element would be too small.

A solution of this problem is afl'orded by the arrangement of connections shown in Fig. 5. It consists in dividing the selfinduct-ion serving in the case of ordinary connections the double purpose of back coupling and coupling with the secondary circuit, and thereby dividing the tension at the tube into two self induction parts C and C serving each purpose separately. With such an arrangement in consequence of the parallel arrangement of the two self inductions, the total inductivity of the intermediate circuit is considerably reduced for equalizing the high cable capacity. Preferably and as shown, the arrangement is so organized that the tube 1 with the coil C and the tuning condenser 3 (together-apparatus A of Fig. 1) are arranged in the cab of the locomotive so that there is an easy access to them, and only the coupling coil G which does not require any attendance is located below in the frame of the locomotive. An ordinary lead cable K having two con ductors connects the two coils C and C, and an extension of the sensitive grid conduit is not required.

Equalization of the cable capacity of the intermediate circuit can'further be efiected by arranging a shortening condenser L actin as a series-capacity in front of the coupling coil C and also, if desired, in connection' with the line-element coil D- Figures 6 and 8 show circuits including such condensers.

Another solution of the aforementioned problem of enabling the apparatus serving for adjustment and requiring attendance to be placed in the cab of the locomotive consists in providing a second circuit arranged on the locomotive and permanently coupled with the generator circuit. The second circuit is normally out of tune with the generator circuit with regards to its frequency, but upon being moved close to the line element, it is b% means of an inductive or capacitive efl'ect rought into resonance with the generator circuit, whereby the desired reaction is obtained.

The inductive effect is illustrated in Fig. 9. The alternating current generator A excites the primary oscillating circuit 12. The'self-induction of the intermediate circuit 13 is divided into a part 4 intended to be coupled with the primary circuit 12 and into a part C intended to be coupled with the secondary circuit l). The tuning of the intermediate circuit with the aid of the adjustable condenser 5 is so chosen that the intermediate circuit is normally out of tune with the oscillating circuit 12. The coupling of the condenser with the secondary circuit D brings the intermediate circuit into resonance with the primary circuit 2 whereby the desired release of the relay B is caused to take place.

The capacitive effect is illustrated in Figs. 10 and 11. To the primary circuit a secondary circuit is permanently coupled, the tuning of which passes through a certain range when parts thereof approach electrical devices which are fixed at places in the line where it is desired that signals shall be transmitted. When a locomotive carrying an element C, such as is shown in Fig. 10 or 11, passes a line element D of appropriate character, a condition of resonance is set up between, the primary and secondary circuits of the sender in the cab of the locomotive, thereby causing the intended re lease of the relay in the primary system to take place. In Figs. 10 and 11, L is the secondary circuit with :the open condenser C, while denotes an insulated condenserplate serving as a line element. Upon C approaching D, the tuning range between the primary circuit and the secondary circuitis travelled through, and in the position of resonance (Fig. 10) the intended release in the primary circuit is effected- The arrangement according to Fig. 11' differs from that shown in Fig. 10 only by connecting the condenser-plate D and one pole of the self-induction 4 of the secondary circuit with the earth. so that the secondary circuit in the position of resonance is closed above earth. Although the invention has been herein-before described as applied to trains, it Will be understood that it may obviously also be applied to vehicles generally in the same manner as when used on trains for transmitting effects of any kind to them. The generator is for instance mounted on themovable body and the means for influencing it (disengaging or releasing means) is fixed to suitable points in the path de scribed by the body.

If it is, for instance, intended to draw the attention of the engine driver to an approaching signal on the line, an optical or acoustic signalling device is connected to the producer of oscillations. When the train runs past the circuit (Fig. 1 D) which is on the line at a certain distance in front of the line signal, the train signal will be.

actuated.

The invention also permits allowance to be madein the simplest manner for the different lengths of braking distances of the shown in Fig. 3.

ger train will therefore for instance only re-- spond to the line circuits intended for such trains and not to the line circuits of fast trains or goods trains. If in special cases a locomotive should be used for several kinds of trains re-adjustment of the wave length.

of its oscillation generator would have to be effected. This method of signaling trains having different braking distances is illustrated diagrammatically in Fig. 12 in which 16 indicates the track and 15 a locomotive carrying an oscillation generator A, signal B and inductance C, similar to like parts S represents the point at which it is desired to stop all trains. It is obvious that trains of different classes have different braking distances, that is, swiftly moving passenger trains must have their brakes applied before slower moving trains in order to cause all to stop at the same point. The tuned circuits D, D and D, all tuned to different frequencies, are placed along the track at different distances from the stopping point. The circuit D is tuned to a frequency corresponding to the devices carried by trains of the longest braking distance. D to devices of shorter braking distance and D' to devices of trains of still shorter braking distance. The circuits on the trains for which D is tuned will not respond to either D or D nor will the circuits on the trains to which D is tuned respond to either D or D. The trains of the different classes will therefore receive their signals at different distances from the stopping point so that their brakes may be applied immediately thereafter 'to brin them all toa full stop at the point S. 0

course the brakes could be controlled directly by the signaling relay if it were desired to make the control of the trains automatic.

The device according to the resent invention may include, in additlon to the frame coil of the generator circuit, an antenna H (Fig. 5) to which the generator can be connected at will as, for example, by a switch J. This device is of importance in cases where a train for any reason is" stopped on theopen line. By making a connection with the antenna it is possible to enter into direct communication with stations or other trains on the line by means of the telegraph or telephone. It goes without saying that in this case a receiver may also be arran ed on the locomotive in order to enable per ect intercourse to be had with the stations.

the generator and arranged to be coupled to the oscillating circuit of the generator so as to withdraw energy from said circuit, said generator including a three-element tube and an oscillating circuit divided into a portion back-coupled to the grid of the tube and a second portion coupled with the line circuit, thus providing two self-inductance circuits serving the purpose separately of back-coupling to the grid and of coupling with the line circuit, and signalling means controlled bytheenergy produced by said generator.

2. An apparatusfor transmitting signal or other effects to traveling. railway trains or other movable bodies by means of electric oscillations, comprising an oscillating current generator carried by the train, a coil on the line forming a closed oscillating circuit tuned to the frequency of the oscillations in the generator and arranged to be coupled to the oscillatin circuit so as to weaken the energy in said circuit, said generator ineluding a three element tube and an oscillating circuit divided into a portion backcoupled to the grid of the tube and a portion coupled with the line circuit, thus providing two self-inductance circuits serving the purpose separately of back-coupling to the grid and of coupling with the line circuit, a long lead cable connectin the two portions of said oscillating circult, and signallin means controlled by the energy produce bythe generator.

3. An apparatus for transmitting signals or other effects to traveling railway trains or other movable bodies by means of electric oscillations, comprising an oscillating current generator carried by the train, and having a coupling coil, a coil on the line forming a closed oscillating circuit tuned to the frequency of the oscillations in the generator clrcuit and arranged to be coupled I with the coil in the generator circuit so as to weaken the energy produced by the generator, a shortening-condenser located in front of the coupling coil of the oscillating circuitfor equalizing the high cable capacity of said circuit, and means controlled by the energy produced by said generator for giving a signal.

4. A method of transmitting signals to trains which consists in classifying. the trains in accordance with the distances within which-they may be stopped when traveling at their normal speeds, providing trains of difi'erent classes with oscillation generators of difl'erent tuning and those of the same class with oscillation generators of like tuning, and providing signal releasing cir-- cuits at different distances in front of the point at which it is desired to bring the trains to a standstill in case of a stop signal, each of the releasing circuits being tuned toco-act with the oscillation v generators of trains of onev class only and being spaced from the stopping point by a distance corresponding to the maximum length of the braking-distances of trains oflsuc h class.

' In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HERMANN GEWEOKE. Witnesses:

MAX 'ABRAHAMsonN, ERNEST WILLsmr. 

